Oak Wilt Season Strikes Southwest Michigan

Picture this scenario. You have a beautiful, stately oak tree in your yard that has provided shade throughout those broiling Michigan summers, but it was damaged by the ice storm that struck Michigan last February. Now that it’s warming up, it's a great time to give it a trim. WRONG!! 

The time to have trimmed the damaged tree was during the colder months that have just passed by. During the period between April 15 and July 15, beetles actively carry spores of fungus from tree to tree, meaning oak trees are at high risk for infection with oak wilt. 

Simeon Wright, a forest health specialist in the DNR’s Forest Resources Division, says, 

Oak trees should not be pruned between April 15 and July 15. These pruning guidelines can help keep the infection from spreading. Once a tree is infected there is no cure. Without expensive treatments, the disease spreads to other trees and may in time kill all nearby oaks

What Can I Do If I Missed The Window To Trim My Oak Tree?
There is one thing you can do until the pruning window reopens. The Michigan Department of Natural Resources recommends that if you have an oak tree that gets damaged during the high-risk period between April 15 to July 15, immediately cover all wounds with tree-wound paint or latex-based paint. It’s not a good idea to do this to other species, because it can reduce the healing process. 

Oak wilt was first confirmed in Michigan in the 1950s and has become common in the lower peninsula. Once a tree has been stricken, it can die within weeks. Symptoms usually start to appear in late June, and affected trees will suddenly begin to wilt from the top down, shedding leaves that could be green or a combination of green/brown. 

The disease can be spread from firewood cut from infected trees. Once infected firewood has been dried for longer than a year, and all the bark loosens, the firewood can no longer spread oak wilt.